When i was 14 years old, my father was 3 times my age. now he is twice my age. how old am i?

When he was 14 his dad was 42
now the child is twice 14... = 28...

Let f be the father's age and his child's age be c.

As the father is 42  14 = 28 years older than the child, f = c + 28.

At the moment f = 2c, hence 2c = c + 28, and so c = 28. That is, the father's child is now 28 years old.

For the first oneA=lxw divided by 2
= 9x6 divided by 2
= 36 divided by 2
= 18

For the second one
A=lxw divided by 2
= 12x3 divided by 2
= 36 divided by 2
= 18

The third one I can’t draw for you but draw a line diagonally from A to C and use the same formula above and they’ll both be the same area because it’s a parallelogram. Hope this helps, I can help you in the comments if you need more help or would like me to expand on any of the three answers